paraffins / salt hydrates / bio-waxes
ChemistryPhase-change material is specified as paraffins / salt hydrates / bio-waxes. Density band ~0.8–1.6 g/cm³.
Darker cells mean a higher score for this topic on that metric.
Strength10
Heat resistance22
Fire performance24
Insulation52
Workability58
Circularity48
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Quick answers
Is Phase-change material non-combustible?
Declared reaction class in this atlas: paraffin = combustible; salts vary. Assemblies still need resistance tests.
Does Phase-change material insulate?
Thermal mark 52/100 versus the atlas. Conductivity note: low-to-moderate; often needs fins or graphite.
What is the density band?
~0.8–1.6 g/cm³
How is it made?
Origin story: NASA / Telkes 1940s–70s; building PCM 2000s (United States / Germany).
Can it be recycled?
Circularity mark 48/100 — editorial, route-specific.
Typical melting or failure heat?
designed 18–28 °C for buildings
heat 22 · fire 24
What holds Phase-change material together is not the nickname. Formula paraffins / salt hydrates / bio-waxes, density ~0.8–1.6 g/cm³.
Meters are atlas-relative. Grades are the SKUs buyers write.
Phases
Microstructure
OrderProcessing sets grain, crystallinity or fibre orientation — the reason two lots of Phase-change material can test differently.
Interfaces
SurfacesCoatings, oxide films, sizings or paper faces often decide weather and fire behaviour more than the bulk brochure.
Defects
FlawsInclusions, voids, knots, pinholes or residual stress start the failures that mill certificates do not list.
Grades
VariantsPhase-change material is a family. Grade names below are the ones buyers actually write on RFQs.
Ageing
TimeMoisture, UV, creep, hydrogen or carbonation shift properties in service. Design to the aged state.
Relative meters
Strength10
Strength is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Heat envelope22
Heat envelope is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Fire behaviour24
Fire behaviour is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Insulation52
Insulation is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Workability58
Workability is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Circularity48
Circularity is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Grades
Paraffin 22–26 °C
Building comfort.Building comfort.
Salt hydrate
Higher latent heat, cycling issues.Higher latent heat, cycling issues.
Microencapsulated
Gypsum, concrete.Gypsum, concrete.
Macro pouches
Retrofit panels.Retrofit panels.
Battery PCM
Higher Tm.Higher Tm.
Bonds
Primary bonding
Phase-change material holds together by ionic/covalent networks.
Secondary forces
Hydrogen bonds, van der Waals stacks or grain-boundary cohesion set toughness and moisture uptake.
Composites & fills
Fillers, fibres, plasticisers or aggregates are part of the real product, not impurities.
Environment film
Oxides, chars, sizings or paints are the layer the world actually meets.
Change the grade, the coating or the moisture and you have a different material with the same English name.
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